阅读说明：本技术 一种高选择性超灵敏的特异性丙二腈荧光探针与应用 (High-selectivity and ultrasensitive specific malononitrile fluorescent probe and application thereof ) 是由 汪鑫 程思雨 柳彩云 张艳 苏美珺 荣晓迪 王坤 李玺威 祝汉闯 于 2021-10-11 设计创作，主要内容包括：本发明涉及一种高选择性超灵敏的特异性丙二腈荧光探针与应用,具体地,本发明的探针可作为丙二腈荧光探针用于丙二腈的快速定量定性检测。这类探针可实现如下的技术效果中的至少一个：可以高特异性地识别丙二腈；可以快速响应丙二腈；可以灵敏地分析丙二腈的浓度；生物毒性低,可以应用生物细胞中的丙二腈成像；合成简单,性质稳定,可以长期保存使用。(The invention relates to a specific malononitrile fluorescent probe with high selectivity and ultrasensitiveness and application thereof, and particularly relates to the probe which can be used as the malononitrile fluorescent probe for rapid quantitative and qualitative detection of malononitrile. Such probes can achieve at least one of the following technical effects: malononitrile can be recognized with high specificity; malononitrile can be quickly responded; the concentration of malononitrile can be sensitively analyzed; the biological toxicity is low, and malononitrile imaging in biological cells can be applied; simple synthesis and stable property, and can be stored for a long time.)

1. A compound having the structure:

wherein: r₁，R₂，R₃，R₄，R₅And R₆Is independently selected from the group consisting of a hydrogen atom, a linear or branched alkyl group, a linear or branched alkoxy group, a sulfonic acid group, an ester group and a hydroxyl group; and wherein R is₁，R₂，R₃，R₄，R₅And R₆May be the same or different.

2. A compound according to claim 1, wherein R is₁，R₂，R₃，R₄，R₅And R₆Are all hydrogen atoms.

3. A fluorescent probe composition for measuring, detecting or screening malononitrile comprising the compound of any one of claims 1-2.

4. The fluorescent probe composition of claim 3, said compound being:

5. the fluorescent probe composition of claim 3 or 4, wherein the fluorescent probe composition further comprises a solvent, an acid, a base, a buffer solution, or a combination thereof.

6. A method for detecting the presence of malononitrile in a sample or determining the level of malononitrile in a sample, comprising:

a) contacting a compound of any one of claims 1-2 with a sample to form a fluorescent compound;

b) determining the fluorescent properties of the fluorescent compound.

7. The method of claim 6, wherein the sample is a chemical sample or a biological sample.

8. The sample of claim 7, comprising a biological sample comprising water, blood, microorganisms, or animal cells or tissues.

9. A compound according to any one of claims 1-2 for use in fluorescence imaging of cells.

10. A kit for measuring, detecting or screening malononitrile, characterized by comprising a compound according to any one of claims 1 to 2.

Technical Field

The invention belongs to the field of fluorescent probes, and particularly relates to a specific malononitrile fluorescent probe with high selectivity and ultrasensitiveness and application thereof in a method for measuring, detecting or screening malononitrile and live cell fluorescence imaging.

Background

Hydrogen Cyanide (HCN) is one of the most dangerous cyanide species, malononitrile (NCCH)₂CN) is a precursor of Hydrogen Cyanide (HCN) in mammalian tissue metabolism, but malononitrile has higher toxicity than hydrogen cyanide, and can be completely converted into hydrogen cyanide in the mammalian tissue metabolism, so that the existence of the malononitrile seriously threatens the life health of organisms. Malononitrile has wide application in production and life, can be used for producing sulfonylurea herbicides such as pyrazosulfuron-ethyl and the like, can also be used for producing herbicide bispyribac-sodium, and can be used for producing diuretic medicines in medicine. As organic synthetic raw materials, the compound can be used for synthesizing a series of important medicaments such as vitamin B1, aminopterin and the like in the aspect of medicine, and has important application in the aspects of synthesizing dyes, pesticides and the like.

Malononitrile, a highly toxic substance, can enter human body through many routes, such as absorption through our skin or invasion through wounds, or inhalation through respiratory tract, and improper eating, and the like, and can cause health hazards. After the malononitrile enters into organisms, the central nervous system can be rapidly paralyzed, respiratory enzymes and hemoglobin in blood can be poisoned, the breathing is difficult, and the cells of the whole body can also be in an internal asphyxia state. Chronic poisoning is easily caused when a small amount of malononitrile enters the human body through the digestive tract. If people use underground water polluted by malononitrile for a long time, symptoms such as headache, dizziness, palpitation and the like can be caused.

Due to the wide application of malononitrile and potential health risks and environmental pollution, the method has the advantages of knowing the property, source and distribution of malononitrile, clarifying the influence on the environment and human body, exploring a safe, rapid and effective detection method, and having very important significance for protecting the environment and human health. At present, a certain amount of research is carried out on the detection of cyanide, but the detection methods of malononitrile are relatively few, the commonly used detection methods of malononitrile mainly comprise the combination of gas chromatography, liquid chromatography and mass spectrometry, and the methods have the limitations that the price of a test instrument is high, the operation of a professional researcher is required, and the applicability to organisms and environment is low. Therefore, it is urgently needed to develop a more sensitive and simple method for detecting malononitrile.

In recent years, fluorescent probes have been the focus of attention of researchers due to their unique advantages of high selectivity, ultrasensitiveness, simplicity of synthesis, and the like. However, few methods for analyzing the fluorescent probe for detecting malononitrile have been reported, and certain defects such as poor selectivity, too complex synthesis and the like still exist. Therefore, the development of the fluorescent probe which has high selectivity, high sensitivity, simple synthesis, good water solubility and specific recognition of malononitrile is of great significance.

Disclosure of Invention

In view of the above, the present invention aims to provide specific malononitrile fluorescent probes with high selectivity and ultrasensitiveness, and uses thereof, wherein the specific malononitrile fluorescent probes have characteristics of simple synthesis, good selectivity, high sensitivity, specific recognition of malononitrile, and the like, and can effectively measure, detect or screen malononitrile under physiological level conditions.

Specifically, the invention provides a compound having a structure represented by formula (I):

in the formula (I), R₁，R₂，R₃，R₄，R₅And R₆Is independently selected from the group consisting of a hydrogen atom, a linear or branched alkyl group, a linear or branched alkoxy group, a sulfonic acid group, an ester group and a hydroxyl group; and wherein R is₁，R₂，R₃，R₄，R₅And R₆May be the same or different.

In some embodiments of the invention, the compound of the invention is R₁，R₂，R₃，R₄，R₅And R₆A compound of formula (ii) which are both hydrogen atoms, having the formula:

the invention also provides a fluorescent probe composition for measuring, detecting or screening malononitrile, which comprises the compound of formula (I) of the invention.

In some embodiments of the invention, the compound of formula (I) has the following structure:

in some embodiments of the invention, the fluorescent probe composition further comprises a solvent, an acid, a base, a buffer solution, or a combination thereof.

The present invention also provides a method for detecting the presence of malononitrile in a sample or measuring the malononitrile content in a sample, comprising:

a) contacting the compound of formula (I) or formula (ii) with a sample to form a fluorescent compound;

b) determining the fluorescent properties of the fluorescent compound.

In some embodiments of the invention, the sample is a chemical sample or a biological sample.

In some embodiments of the invention, the sample is a biological sample comprising water, blood, microorganisms, or animal cells or tissues.

The invention also provides a kit for detecting the presence of malononitrile in a sample or determining the level of malononitrile in a sample, comprising the compound of formula (I) or formula (ii).

The invention also provides application of the compound shown in the formula (I) or the formula (II) in cell fluorescence imaging.

Compared with the prior art, the invention has the following remarkable advantages and effects:

(1) fast response

The fluorescent probe provided by the invention can quickly respond to instantaneous malononitrile of malononitrile, and is favorable for quick detection of malononitrile.

(2) Good specificity

The fluorescent probe can selectively perform specific reaction with malononitrile to generate a product with fluorescence change, and compared with other common metal ions and other substances in a living body, the fluorescent probe has higher selectivity and strong anti-interference capability.

(3) Has low biological toxicity and can be applied under physiological level conditions

The fluorescent probe has the characteristic of low toxicity, and is favorable for being applied to the detection or imaging of malononitrile in cell samples for a long time.

(4) High sensitivity

The fluorescent probe provided by the invention reacts with malononitrile very sensitively, so that the detection of the malononitrile is facilitated.

(5) Simple synthesis

The malononitrile fluorescent probe is simple to synthesize and beneficial to commercial popularization and application.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a graph showing the response time before and after probe (10. mu.M) was added to malononitrile (0.5 mM);

FIG. 2(a) is a graph showing the change in fluorescence spectrum before and after addition of probe (10. mu.M) to malononitrile (0-1 mM); (b) the probe (10. mu.M) quantitatively analyzes working curves of different concentrations of malononitrile (0-1mM), with the ordinate being the fluorescence intensity value at 580 nm.

FIG. 3(a) is the change in fluorescence spectrum before and after addition of probe (10. mu.M) to malononitrile (0-8. mu.M); (b) is a working curve for the quantitative analysis of the probe (10. mu.M) on different concentrations of malononitrile (0-8. mu.M), with the ordinate being the fluorescence intensity at 580 nm.

FIG. 4(a) is a graph showing the change in absorbance before and after adding a probe (10. mu.M) to malononitrile (0 to 8. mu.M); (b) after the probe (10 mu M) is added into malononitrile (the concentrations from left to right are 0, 5 mu M, 10 mu M, 20 mu M and 30 mu M respectively), the color of the solution changes with naked eyes;

FIG. 5 Effect of different ion analytes (all 100. mu.M except where indicated) on the fluorescence intensity of probes (10. mu.M), the bar graphs represent the fluorescence intensity of the probes at 580nm under different test conditions;

FIG. 6 fluorescence intensity of probes (10. mu.M) after recognition of malononitrile (100. mu.M) in the presence of different ionic analytes (all 100. mu.M except as indicated by the special indication), the bar graph representing the fluorescence intensity of the probes at 580nm under different test conditions;

FIG. 7 is a toxicity analysis of HeLa cells at respective probe concentrations: 0 μ M, 5 μ M, 10 μ M, 20 μ M, 30 μ M;

FIG. 8 is a confocal fluorescence imaging of Hela cells;

FIG. 9 shows the experimental results of the probe effect on the behavioral characteristics of zebrafish. (A) Representative trace plots of probe (0,10 μ M) treated zebrafish larvae. (B) Relative swimming time of zebra fish larvae after probe treatment (0,10 μ M); (C) and (4) moving distance.

FIG. 10 is a confocal fluorescence imaging of zebrafish.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and should not be used to limit the scope of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, belong to the scope of the present invention.

Example 1: testing time dynamics of fluorescent probes

A10 mL test system with a probe concentration of 10. mu.M was prepared, 0.5mM malononitrile was added to the test system, and the change in fluorescence intensity was measured by a fluorescence spectrometer immediately after shaking uniformly. The above measurement was carried out in a system of ethanol, water, 5:5(10mM PBS, pH 8.0), the probe used was the compound of formula (ii), and the fluorescence spectrum was measured at 25 ℃.

As is clear from FIG. 1, when malononitrile is added, the fluorescence intensity reaches a maximum value and remains substantially unchanged around 60min, which indicates that the probe can respond to malononitrile quickly and provide a rapid analysis method for the measurement of malononitrile.

Example 2: concentration gradient of fluorescent probe for malononitrile (0-1mM)

A plurality of parallel samples with the probe concentration of 10 mu M are arranged in a 10mL colorimetric tube, malononitrile with different concentrations (0-1mM) is added into the test system, the test system is shaken uniformly and then stands for 60 minutes, and then the fluorescence intensity change of the test system is tested by a fluorescence spectrometer. The above measurement was carried out in a system of ethanol, water, 5:5(10mM PBS, pH 8.0), the probe used was the compound of formula (ii), and the fluorescence spectrum was measured at 25 ℃.

The fluorescence intensity change was measured by fluorescence spectroscopy, and as is clear from fig. 2(a) and 2(b), in the low concentration range, the fluorescence intensity at 580nm gradually increased with the increase of the malononitrile concentration, and the response factor was about 60 times at the malononitrile concentration and the equivalent probe (10 μ M), and was as high as 160 times at the malononitrile concentration of 1mM, indicating that the probe can achieve sensitive detection of malononitrile.

Example 3: concentration gradient of fluorescent probe to malononitrile (0-8. mu.M)

A plurality of parallel samples with the probe concentration of 10 mu M are arranged in a 10mL colorimetric tube, malononitrile with different concentrations (0-8 mu M) is added into the test system, the test system is shaken uniformly and then stands for 60 minutes, and then the fluorescence intensity change of the test system is tested by a fluorescence spectrometer. The above measurement was carried out in a system of ethanol, water, 5:5(10mM PBS, pH 8.0), the probe used was the compound of formula (ii), and the fluorescence spectrum was measured at 25 ℃.

As is clear from FIG. 3(a), the fluorescence intensity at 580nm gradually increased with increasing malononitrile concentration; also, it can be seen from FIG. 3(b) that the probe (10. mu.M) shows a good linear relationship between the fluorescence intensity at 580nm and the malononitrile concentration after the probe (10. mu.M) is added to malononitrile (0 to 10. mu.M), which demonstrates that the malononitrile can be quantitatively analyzed with the aid of the fluorescent probe.

Example 4: testing of the absorbance change and naked eye Capacity test of fluorescent probes for different concentrations of Malononitrile

Preparing a plurality of parallel samples with the probe concentration of 10 mu M in a 10mL colorimetric tube, adding malononitrile with different concentrations (0-8 mu M) into the test system, shaking uniformly, standing for 60 minutes, and testing the change of the fluorescence intensity by using an ultraviolet spectrophotometer. The above measurement was carried out in a system of ethanol, water, 5:5(10mM PBS, pH 8.0), the probe used was the compound of formula (ii), and the absorption spectrum was measured at 25 ℃.

As is clear from FIG. 4(a), the absorbance at 510nm gradually increased with the increase in the malononitrile concentration.

A plurality of 10. mu.M probe concentrations of parallel samples were prepared in 10mL cuvettes, and then different concentrations of malononitrile (0, 5. mu.M, 10. mu.M, 20. mu.M, 30. mu.M) were added to the test system, shaken well and allowed to stand.

As can be seen from fig. 4(b), as the amount of malononitrile added increases, the color of the solution changes significantly, which demonstrates that the naked-eye qualitative analysis of malononitrile can be performed by means of the fluorescent probe.

Example 5: testing the selectivity of fluorescent probes

A plurality of parallel samples with the probe concentration of 10 mu M are configured in a 10mL colorimetric tube, then different analytes (the analytes are respectively blank, ferric ion, copper ion, iodide ion, fluoride ion, bisulfite, calcium ion, sodium ion, potassium ion, lysine, aspartic acid, glutamine, glutathione, homocysteine, cysteine and malononitrile; except special marks, the concentrations of other analytes are all 100 mu M) are added into a test system, the test system is shaken uniformly and then kept stand for 60 minutes, and then a fluorescence spectrometer is used for testing the change of the fluorescence intensity. The above measurement was carried out in a system of ethanol, water, 5:5(10mM PBS, pH 8.0), the probe used was the compound of formula (ii), and the fluorescence spectrum was measured at 25 ℃.

As is clear from FIG. 5, only the addition of malononitrile causes a strong change in the fluorescence intensity of the probe, while the effect of the other analytes is almost negligible. Experiments prove that the probe has higher selectivity on malononitrile, and is favorable for detection and analysis of malononitrile.

Example 6: testing the interference rejection of fluorescent probes

A plurality of parallel samples with probe concentration of 10 mu M are configured in a 10mL colorimetric tube, then different analytes (the analytes with the numbers A-P are blank, ferric ion, copper ion, iodide ion, fluoride ion, bisulfite, calcium ion, sodium ion, potassium ion, lysine, aspartic acid, glutamine, glutathione, homocysteine, cysteine and blank respectively; except for special marks, the concentrations of other analytes are all 100 mu M) are added into a test system, malononitrile (100 mu M) is added into other components except the first blank group, the test system is stood for 60 minutes after being shaken uniformly, and then a fluorescence spectrometer is used for testing the change of fluorescence intensity. The above measurement was carried out in a system of ethanol, water, 5:5(10mM PBS, pH 8.0), the probe used was the compound of formula (ii), and the fluorescence spectrum was measured at 25 ℃.

As can be clearly seen from FIG. 6, the addition of other analytes hardly interferes with the detection of malononitrile by the fluorescent probe, and experiments prove that the probe has high anti-interference capability on malononitrile, thereby being beneficial to the detection and analysis of malononitrile.

Example 7: toxicity test of fluorescent probe on HeLa cells

In DMEM high-glucose medium, at a density of 1X10 in 96-well plates⁶The Hela cells were plated and incubated in a 37 ℃ incubator containing 5% CO 2/95% airAnd (5) nourishing. After 12 hours of culture, probes were added to the cells at final concentrations of 0, 5, 10, 20, and 30. mu.M, respectively, and after further 24 hours of culture, cell viability was measured using CCK8 kit

The probe used is a compound of formula (II).

As is clear from FIG. 7, the probe has the characteristic of low toxicity, and can be applied to real-time detection of malononitrile in cell samples for a long time.

Example 8 Coconfocal fluorescence imaging of fluorescent probes to exogenous malononitrile in HeLa cells

Dividing the HeLa cells into five groups, using group a as a blank control group and group b with probe (10 μ M) for 20 min; group c was incubated with probe (10. mu.M) for 20min and malononitrile (5. mu.M) for 60 min; group d was incubated with probe (10. mu.M) for 20min, followed by malononitrile (20. mu.M) for 60 min; group e was incubated with probe (10. mu.M) for 20min and malononitrile (50. mu.M) for 60 min. Finally, confocal microscopy imaging was performed on the five groups of cells, and the test results are shown in fig. 8.

The probe used is a compound of formula (II).

As is clear from fig. 8, HeLa incubated with this probe and different concentrations of malononitrile exhibited different fluorescence intensities, and the fluorescence intensity increased significantly as the concentration of malononitrile increased. Experiments prove that the probe can realize the detection of exogenous malononitrile in living cells.

Example 9 Zebra fish behavioral experiments

In order to better verify the biological imaging ability of the probe, a series of studies were conducted on zebrafish.

Zebrafish larvae were divided into two groups, one group was left untreated and one group was incubated with probe (10 μ M) and behavioral experiments were performed to further test the safety of the probe. The test results are shown in fig. 9, where fig. 9(a) is the behavioral trajectory of zebrafish, and red, green and black lines represent fast, medium and slow movements, respectively, as shown, the trajectories of probe-treated zebrafish and control group are not significantly different. As can be seen from fig. 9(B) and 9(C), the treated zebrafish did not differ much from the control group in moving time, moving distance and speed, indicating that the probe did not negatively affect the zebrafish.

Example 10: confocal fluorescence imaging of exogenous malononitrile in zebra fish by fluorescent probe

Dividing zebrafish into five groups, using group a as blank control group and group b with probe (10 μ M) for 20 min; group c was incubated with probe (10. mu.M) for 20min and malononitrile (5. mu.M) for 60 min; group d was incubated with probe (10. mu.M) for 20min, followed by malononitrile (20. mu.M) for 60 min; group e was incubated with probe (10. mu.M) for 20min and malononitrile (50. mu.M) for 60 min. Finally, confocal microscopy imaging was performed on the five groups of cells, and the test results are shown in fig. 10.

As is clear from fig. 10, zebrafish incubated with the probe and different concentrations of malononitrile exhibited different fluorescence intensities, and the fluorescence intensity increased significantly as the concentration of malononitrile increased. Experiments prove that the probe can realize the detection of exogenous malononitrile in living cells.

The probe used in the above test is a compound of formula (II).

Although the present invention has been described in the above-mentioned embodiments, it is to be understood that the present invention may be further modified and changed without departing from the spirit of the present invention, and that such modifications and changes are within the scope of the present invention.